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Introduction
Water is made up of the chemical elements hydrogen and oxygen, which are linked together by covalent bonds and exist in gaseous, liquid, and solid phases. H2O is the chemical formula for water. It is one of the most abundant and essential molecules on the planet. Water is the most necessary element for human life, second only to oxygen. Without food, one can survive for a few days, but not without water. It also serves as a solvent for a variety of compounds and is involved in a variety of chemical reactions. Water is also a supply of heavy water (D2O), which is needed to control neutron speed in nuclear reactors.
States of water
Water is one of the two formal names for the chemical molecule H2O, along with oxidane; it is also the state of water of H2O. The solid phase of water, ice, and the gaseous phase, water vapour or steam, are the other two prevalent forms of matter. Heat can produce phase transitions such as freezing (from water to ice), melting (from ice to water), vaporisation (from water to vapour), condensation (from vapour to water), sublimation (from ice to vapour), and deposition (from ice to vapour) (vapour to ice).
Density of water
Water is unique among liquids in that it loses density as it freezes. At 3.98 °C (39.16 °F), it reaches the maximum density of 1,000 kg/m3 (62.43 lb/cu ft) at 1 atm pressure. Ice has a density of 917 kg/m3 (57.25 lb/cu ft) and expands by 9%. This expansion can apply tremendous pressure, causing pipes to explode and rocks to shatter (Frost weathering).
Taste and odour
Although humans have specific sensors that detect the presence of water in their mouths and frogs are thought to be able to smell it, pure water is generally thought to be tasteless and odourless. However, water from everyday sources (including bottled mineral water) typically contains a large number of dissolved chemicals, which can cause it to have a variety of tastes and scents. Humans and other animals have evolved sensors that allow them to assess the mobility of water by avoiding salty or rotten water.
Bond angle
The hydrogen atoms in a water molecule form a 104.5° angle with the oxygen atoms. The hydrogen atoms are near two of the tetrahedron’s corners, which are centred on the oxygen. The lone pairs of valence electrons in the other two corners are not involved in the bonding. The atoms would form a 109.5° angle in a perfect tetrahedron, but the repulsion between the lone pairs is larger than the repulsion between both the hydrogen atoms. The length of the O–H bond is approximately 0.096 nm.
Hydrogen bonding
Due to its polarity, a molecule of water in the liquid or solid state can form up to four hydrogen bonds with neighbouring molecules. In most liquids, hydrogen bonds are around ten times stronger than the Van der Waals force, which draws molecules together. Water’s melting and boiling temperatures are substantially greater than those of other comparable substances like hydrogen sulphide because of this.
Reactivity
Alkali metals and alkaline earth metals such as potassium, sodium, calcium, and caesium, which are more electropositive than hydrogen, displace hydrogen from water, creating hydroxides and releasing hydrogen. Carbon reacts with steam at high temperatures to produce carbon monoxide and hydrogen.
Conclusion
The most common chemical found in living creatures is water. Water makes up about 62 percent of the human body. Water is translucent and virtually colourless in its liquid state. Blue is the colour of large amounts of liquid water and ice. The weak absorption of light at the red end of the visible spectrum accounts for the blue colour of water. Pure water has no flavour or odour.
